KR101076516B1 - Plasma processing method and apparatus - Google Patents

Abstract

Provided are a plasma treatment method and apparatus capable of improving the uniformity of treatment, including the doping concentration.

In addition to stopping the exhaust in the vacuum chamber 900, supplying the gas into the vacuum chamber and stopping the mixed gas of helium gas and diborane gas in the vacuum chamber, plasma is generated in the vacuum chamber, and the sample electrode By supplying high frequency power, boron is introduced near the surface of the substrate 9.

Description

Plasma treatment method and apparatus {PLASMA PROCESSING METHOD AND APPARATUS}

1A is a cross-sectional side view showing the configuration of a plasma doping apparatus used in a first embodiment of the present invention.

Fig. 1B is a plan view showing a shape of a vacuum chamber or the like of the plasma doping apparatus used in the first embodiment.

1C is a plan view showing a shape of a vacuum chamber or the like of a plasma doping apparatus according to a modification of the first embodiment.

1D is a plan view showing a shape of a vacuum chamber or the like of the plasma doping apparatus according to another modification of the first embodiment;

The figure which shows the sheet resistance measurement result in 1st Embodiment of this invention.

3 is a cross-sectional view showing the configuration of a conventional plasma doping apparatus used for the description in the first embodiment of the present invention.

4 is a cross-sectional view illustrating a configuration of a plasma doping apparatus used in a second embodiment of the present invention.

Fig. 5 is a sectional view showing the structure of a plasma doping apparatus used in a third embodiment of the present invention.                 

Fig. 6 is a sectional view showing the structure of a plasma doping apparatus used in a fourth embodiment of the present invention.

Fig. 7A is a sectional view showing the structure of a plasma doping apparatus used in a fifth embodiment of the present invention.

7B is a front view of an example of a shielding plate of a plasma doping apparatus used in a fifth embodiment of the present invention.

Fig. 7C is a perspective view of the shield plate of the plasma doping apparatus used in the fifth embodiment, seen from the transverse direction.

Fig. 7D is a perspective view of the shield plate of the plasma doping apparatus used in the fifth embodiment as seen from below.

7E is a front view of another example of a shield plate of the plasma doping apparatus used in the fifth embodiment.

Fig. 7F is a perspective view of the other example of the shielding plate of the plasma doping apparatus used in the fifth embodiment, seen from the transverse direction.

Fig. 7G is a perspective view of the other example of the shielding plate of the plasma doping apparatus used in the fifth embodiment, as seen from below.

8 is a cross-sectional view illustrating a configuration of a plasma doping apparatus used in a modification of the fifth embodiment of the present invention.

FIG. 9 is a view showing a condition table in a 38 liter vacuum chamber in a specific example of the plasma doping apparatus used in the first, second, third, fourth and fifth embodiments of the present invention. FIG.

Fig. 10 is a specific example of the plasma doping apparatus used in the fifth embodiment of the present invention. Fig. 10 is a diagram of a condition table in a 38-liter vacuum chamber when the exhaust is stopped first and the gas supply is stopped at the same time as 4 Pa.

Fig. 11 is another specific example of the plasma doping apparatus used in the fifth embodiment of the present invention. Fig. 11 is a diagram of a condition table in a 38-liter vacuum chamber when gas supply is first stopped and exhaust is stopped at the same time as 2 Pa. .

Fig. 12A is a sectional view showing the structure of a plasma doping apparatus used in a sixth embodiment of the present invention.

12B is a view showing a condition table in a 38-liter vacuum chamber in a specific example of the plasma doping apparatus used in the sixth embodiment of the present invention.

13 is a cross-sectional view illustrating a configuration of a plasma doping apparatus used in a conventional example.

14 is a cross-sectional view illustrating a configuration of a plasma doping apparatus used in a conventional example.

15 shows sheet resistance measurement results in a conventional example.

DESCRIPTION OF THE REFERENCE NUMERALS

1: vacuum vessel 2: gas supply

3: turbomolecular pump 4: pressure regulating valve

5: high frequency power supply 6: sample electrode                 

7: dielectric window 8: coil

9: substrate 10: high frequency power supply

11: gas inlet 12: exhaust port

This invention relates to the plasma processing method and apparatus which represent the plasma doping which introduce | transduces an impurity into the surface of solid samples, such as a semiconductor substrate.

As a technique for introducing impurities into the surface of a solid sample, a plasma doping method is known in which impurities are ionized and introduced into a solid with low energy (see, for example, US Patent No. 4912065). Fig. 13 shows a schematic configuration of a plasma processing apparatus used in the plasma doping method as a conventional impurity introduction method described in the above-mentioned US Patent No. 4912065. In FIG. 13, a sample electrode 206 for mounting a sample 209 made of a silicon substrate is provided in the vacuum chamber 201. A gas supply device 202 for supplying a doping source gas containing an element required in the vacuum chamber 201, for example, B ₂ H ₆ , and a pump 203 for depressurizing the inside of the vacuum chamber 201. ) Is installed, and the inside of the vacuum chamber 201 can be maintained at a predetermined pressure. Microwaves are emitted from the microwave waveguide 219 into the vacuum chamber 201 through the quartz plate 207 serving as the dielectric window. Due to the interaction between the microwaves and the direct-current magnetic field formed from the electromagnet 214, a magnetic field microwave plasma (electron cyclotron resonance plasma) 220 is formed in the vacuum chamber 201. The high frequency power supply 210 is connected to the sample electrode 206 through the capacitor 221 to control the potential of the sample electrode 206. In addition, the gas supplied from the gas supply device 202 is introduced into the vacuum chamber 201 from the gas inlet 211, and is exhausted from the exhaust port 212 to the pump 203.

In the plasma processing apparatus having such a configuration, the doping source gas introduced from the gas inlet 211, for example, B ₂ H _6, is converted into plasma by the plasma generating means composed of the microwave waveguide 219 and the electromagnet 214. The boron ions in the plasma 220 are introduced to the surface of the sample 209 by the high frequency power supply 210.

After the metal wiring layer is formed on the sample 209 into which impurities are introduced in this manner, a thin oxide film is formed on the metal wiring layer in a predetermined oxidizing atmosphere, and then the gate electrode is formed on the sample 209 with a CVD apparatus or the like. If formed, an MOS transistor is generated as an example.

By the way, a gas containing an impurity which is electrically activated when introduced into a sample such as a silicon substrate, such as a doped raw material gas composed of B ₂ H ₆ , has a problem that the risk is generally high.

In the plasma doping method, all of the substances contained in the doping source gas are introduced into the sample. In the case where the doping source gas composed of B ₂ H ₆ is described as an example, only impurities that are effective when introduced into the sample are boron, but hydrogen is also introduced into the sample at the same time. When hydrogen is introduced into the sample, there is a problem that lattice defects occur in the sample during the subsequent heat treatment such as epitaxial growth.

Thus, the impurity solid containing impurities which are electrically activated when introduced into the sample 209 is disposed in the vacuum chamber 201, and the plasma 220 of the rare gas is generated in the vacuum chamber 201. A method of separating impurities from impurity solids by sputtering impurity solids with ions of an inert gas has been devised (see, for example, Japanese Patent Laid-Open No. 09-115851). Fig. 14 shows a schematic configuration of a plasma doping apparatus used in the plasma doping method as a conventional impurity introduction method described in Japanese Patent Laid-Open No. 09-115851. In FIG. 14, a sample electrode 206 for mounting a sample 209 made of a silicon substrate is provided in the vacuum chamber 201. A gas supply device 202 for supplying an inert gas into the vacuum chamber 201 and a pump 203 for depressurizing the inside of the vacuum chamber 201 are provided to maintain the inside of the vacuum chamber 201 at a predetermined pressure. Microwaves are emitted from the microwave waveguide 219 into the vacuum chamber 201 through the quartz plate 207 serving as the dielectric window. Due to the interaction between the microwaves and the direct-current magnetic field formed from the electromagnet 214, a magnetic field microwave plasma (electron cyclotron resonance plasma) 220 is formed in the vacuum chamber 201. The high frequency power supply 210 is connected to the sample electrode 206 through the capacitor 221 to control the potential of the sample electrode 206. In addition, an impurity solid 222 containing an impurity element, for example, boron, is provided on the solid support 223, and the potential of the solid support 223 is connected via the capacitor 224 to the high frequency power supply 225. Controlled by In addition, the gas supplied from the gas supply device 202 is introduced into the vacuum chamber 201 from the gas inlet 211, and is exhausted from the exhaust port 212 to the pump 203.

In the plasma doping apparatus having such a configuration, an inert gas introduced from the gas inlet 211, for example, argon (Ar), is converted into plasma by a plasma generating means composed of a microwave waveguide 219 and an electromagnet 214. A part of the impurity element scattered in the plasma by sputtering from the impurity solid 222 is ionized and introduced into the surface of the sample 209.

However, in the conventional method, there is a problem that it is difficult to uniformly dop the impurities onto the surface of the sample.

FIG. 15 shows a sheet in the case of doping boron in a silicon semiconductor substrate 209 having a diameter of 200 mm when the x-axis is set from the upper side to the lower side in FIG. 13 in the conventional plasma doping apparatus shown in FIG. sheet) This is the result of measuring the resistance. As is apparent from FIG. 15, the sheet resistance is high at the side close to the gas inlet 211 (upper side in FIG. 13) and low at the side close to the exhaust port 212 (lower side in FIG. 13). This is considered to be due to the nonuniformity of the boron ion density as an impurity source, which is caused by the influence of the nonuniformity of the gas flow, in other words, the nonuniformity of the pressure, the nonuniformity of the flow rate, the nonuniformity of the boron partial pressure, and the like.

It is an object of the present invention to provide a plasma processing method and apparatus which can improve the uniformity of treatment including the doping concentration in view of the above conventional problems.

In order to achieve the above object, the present invention is configured as follows.

According to a first aspect of the present invention, there is provided a plasma processing method for introducing impurities into a sample or a film on the surface of the sample.

Mounting the sample on the sample electrode in the vacuum chamber,

Supplying gas into the vacuum chamber from the gas inlet of the vacuum chamber while exhausting the inside of the vacuum chamber from the exhaust port of the vacuum chamber,

The exhaust flow rate from the vacuum chamber through the exhaust port is set to zero or almost zero, and the supply flow rate of the gas from the gas inlet is set to zero or almost zero,

Provided is a plasma processing method comprising generating plasma in the vacuum chamber by supplying high frequency power to a plasma source to introduce impurities into the sample or a film on the surface of the sample.

According to this configuration, the exhaust flow rate is set to 0 or almost 0, and the high frequency power is supplied to the plasma source to generate the plasma in the vacuum chamber while the supply flow rate of the gas is set to 0 or almost 0. By being able to perform the plasma treatment without being affected by the gas flow, it is possible to improve the uniformity of the treatment, including the doping concentration.

According to a second aspect of the present invention, there is provided a plasma treatment method for introducing impurities into a sample or a film on the surface of the sample.                     

Mounting the sample on the sample electrode in the vacuum chamber,

While evacuating the inside of the vacuum chamber from the exhaust port of the vacuum chamber, the vacuum chamber is provided from the gas introduction port provided so that a shortest flow path connecting the exhaust port and the gas inlet port of the vacuum chamber avoids an upper space of the surface of the sample. The gas is supplied into the chamber, and the flow of the gas supplied from the gas inlet of the vacuum chamber into the vacuum chamber is directed to the exhaust port while avoiding an upward space of the surface of the sample;

The exhaust flow rate from the vacuum chamber through the exhaust port is set to zero or almost zero, and the supply flow rate of the gas from the gas inlet is set to zero or almost zero,

Provided is a plasma processing method comprising generating plasma in the vacuum chamber by supplying high frequency power to a plasma source to introduce impurities into the sample or the film on the surface of the sample.

According to this configuration, the exhaust flow rate is set to 0 or almost 0, and the high frequency power is supplied to the plasma source to generate the plasma in the vacuum chamber while the supply flow rate of the gas is set to 0 or almost 0. Plasma processing can be performed without being affected by the gas flow, thereby improving the uniformity of the treatment, including the doping concentration. Further, since the flow of the gas supplied from the gas inlet of the vacuum chamber into the vacuum chamber is directed toward the exhaust port while avoiding an upward space of the surface of the sample, particles (dust) do not fall on the sample. As a result, the plasma treatment can be performed to improve the uniformity of the treatment including the doping concentration.

According to the third aspect of the present invention, the gas can be supplied into the vacuum chamber from the gas inlet provided so that the shortest flow path connecting the exhaust port and the gas inlet port avoids an upward space of the surface of the sample while exhausting. A plasma processing method according to a second aspect is provided wherein the gas is supplied into the vacuum chamber from the gas inlet provided at a portion closer to the exhaust port than the sample electrode.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. Further, a gas inlet is provided at a portion closer to the exhaust port than the sample electrode, so that the flow of the gas supplied from the gas inlet of the vacuum chamber into the vacuum chamber causes an upward space of the surface of the sample from the gas inlet. Since it does not face, it faces the said exhaust port, plasma processing can be performed without particle | grains (dust) falling to a sample.

According to the fourth aspect of the present invention, the gas can be supplied into the vacuum chamber from the gas inlet which is provided such that the shortest flow path connecting the exhaust port and the gas inlet port avoids an upward space of the surface of the sample while exhausting. A plasma processing method according to a second aspect is provided wherein the gas is supplied into the vacuum chamber from the gas inlet provided at a portion below the sample electrode.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. In addition, since the gas inlet is provided at a portion below the sample electrode, plasma processing can be performed without dropping particles (dust) to the sample.

According to a fifth aspect of the present invention, the gas can be supplied into the vacuum chamber from the gas inlet provided so that the shortest flow path connecting the exhaust port and the gas inlet port avoids an upward space of the surface of the sample while exhausting. A plasma processing method according to the second aspect is provided, wherein the gas is supplied from the gas inlet port toward the exhaust port.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. In addition, since gas is supplied from the gas inlet to the exhaust port, plasma processing can be performed without dropping particles (dust) to the sample.

According to the sixth aspect of the present invention, the gas can be supplied into the vacuum chamber from the gas inlet provided so that the shortest flow path connecting the exhaust port and the gas inlet port avoids an upward space of the surface of the sample while exhausting. A plasma processing method according to the second aspect is provided, wherein the gas is supplied from the gas inlet to the exhaust apparatus for performing the exhaust.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. In addition, since gas is supplied from the gas inlet toward the exhaust apparatus, plasma processing can be performed without dropping particles (dust) to the sample.

According to a seventh aspect of the present invention, the gas can be supplied into the vacuum chamber from the gas inlet provided so that the shortest flow path connecting the exhaust port and the gas inlet port avoids an upward space of the surface of the sample while exhausting. A plasma processing method according to the second aspect is provided, wherein the gas is supplied into the vacuum chamber from the gas introduction port provided at a portion not in contact with the plasma even when the plasma is generated.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. In addition, since the gas inlet is provided at the site which is not in contact with the plasma even in the step of generating the plasma, the plasma treatment can be performed without dropping particles (dust) on the sample.

According to the eighth aspect of the present invention, the gas can be supplied into the vacuum chamber from the gas inlet provided so that the shortest flow path connecting the exhaust port and the gas inlet port avoids an upward space of the surface of the sample while exhausting. The plasma processing method according to the second aspect wherein the gas is supplied from the gas inlet to the vacuum chamber while being shielded from the plasma by a shielding plate disposed near the gas inlet at the time of generating the plasma. To provide.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. In addition, since the gas inlet is provided at a portion shielded from the plasma even in the step of generating the plasma, the plasma treatment can be performed without dropping particles (dust) to the sample.

According to a ninth aspect of the present invention, there is provided a plasma processing method for introducing an impurity into a sample or a film on a surface of a sample.

Mounting the sample on the sample electrode in the vacuum chamber,

Exhaust the inside of the vacuum chamber from the exhaust port of the vacuum chamber,

After the exhaust flow rate from the vacuum chamber through the exhaust port is set to 0 or nearly 0, the shortest flow path connecting the exhaust port and the gas inlet port of the vacuum chamber is provided to the gas inlet port installed to avoid the space above the surface of the sample. The gas is supplied into the vacuum chamber from the gas inlet of the vacuum chamber, and the flow of the gas supplied into the vacuum chamber is directed to the exhaust port while avoiding an upward space of the surface of the sample,

The supply flow rate of the gas from the gas inlet is made zero or almost zero,

Provided is a plasma processing method comprising generating plasma in the vacuum chamber by supplying high frequency power to a plasma source to introduce impurities into the sample or a film on the surface of the sample.

According to this configuration, the exhaust flow rate is set to 0 or almost 0, and the high frequency power is supplied to the plasma source to generate the plasma in the vacuum chamber while the supply flow rate of the gas is set to 0 or almost 0. Plasma processing can be performed without being affected by the gas flow, thereby improving the uniformity of the treatment, including the doping concentration. Further, since the flow of the gas supplied from the gas inlet of the vacuum chamber into the vacuum chamber is directed toward the exhaust port while avoiding an upward space of the surface of the sample, particles (dust) do not fall on the sample. Plasma processing can be performed.

According to the tenth aspect of the present invention, after setting the exhaust flow rate from the vacuum chamber through the exhaust port to zero or almost zero, the shortest flow path connecting the exhaust port and the gas inlet port avoids an upward space on the surface of the sample. The plasma processing method according to the ninth aspect, wherein the gas is supplied into the vacuum chamber from the gas inlet provided at a portion closer to the exhaust port than the sample electrode when the gas is supplied from the gas inlet provided to the gas chamber. To provide.

According to this configuration, the exhaust flow rate is set to 0 or almost 0, and the high frequency power is supplied to the plasma source to generate the plasma in the vacuum chamber while the supply flow rate of the gas is set to 0 or almost 0. Plasma processing can be performed without being affected by the gas flow, thereby improving the uniformity of the treatment, including the doping concentration. Further, since the gas inlet is provided at a portion closer to the exhaust port than the sample electrode, the plasma treatment can be performed without dropping particles (dust) on the sample.

According to the eleventh aspect of the present invention, after setting the exhaust flow rate from the vacuum chamber through the exhaust port to zero or almost zero, the shortest flow path connecting the exhaust port and the gas inlet port avoids an upper space of the surface of the sample. The plasma processing method according to the ninth aspect is provided so that the gas is supplied into the vacuum chamber from the gas inlet provided at a portion below the sample electrode when the gas is supplied into the vacuum chamber from the gas inlet provided so as to be provided. do.

According to this configuration, the exhaust flow rate is set to 0 or almost 0, and the high frequency power is supplied to the plasma source to generate the plasma in the vacuum chamber while the supply flow rate of the gas is set to 0 or almost 0. Plasma processing can be performed without being affected by the gas flow, thereby improving the uniformity of the treatment, including the doping concentration. In addition, since the gas inlet is provided at a portion below the sample electrode, plasma processing can be performed without dropping particles (dust) to the sample.

According to a twelfth aspect of the present invention, after setting the exhaust flow rate from the vacuum chamber through the exhaust port to zero or almost zero, the shortest flow path connecting the exhaust port and the gas inlet port avoids an upper space of the surface of the sample. The plasma processing method according to the ninth aspect is provided so that the gas is supplied from the gas inlet toward the exhaust port when the gas is supplied from the gas inlet to the vacuum chamber.

According to this configuration, the exhaust flow rate is set to 0 or almost 0, and the high frequency power is supplied to the plasma source to generate the plasma in the vacuum chamber while the supply flow rate of the gas is set to 0 or almost 0. Plasma processing can be performed without being affected by the gas flow, thereby improving the uniformity of the treatment, including the doping concentration. In addition, since gas is supplied from the gas inlet to the exhaust port, plasma processing can be performed without dropping particles (dust) to the sample.

According to a thirteenth aspect of the present invention, after setting an exhaust flow rate from the vacuum chamber through the exhaust port to zero or almost zero, the shortest flow path connecting the exhaust port and the gas inlet port avoids an upward space on the surface of the sample. When the gas is supplied into the vacuum chamber from the gas inlet provided so as to be supplied, the plasma processing method according to the ninth aspect is provided so that the gas is supplied from the gas inlet toward the exhaust apparatus for performing the exhaust.

According to this configuration, the exhaust flow rate is set to 0 or almost 0, and the high frequency power is supplied to the plasma source to generate the plasma in the vacuum chamber while the supply flow rate of the gas is set to 0 or almost 0. Plasma processing can be performed without being affected by the gas flow, thereby improving the uniformity of the treatment, including the doping concentration. In addition, since gas is supplied from the gas inlet toward the exhaust apparatus, plasma processing can be performed without dropping particles (dust) to the sample.

According to a fourteenth aspect of the present invention, when the gas is supplied into the vacuum chamber from the gas introduction port provided so that the shortest flow path connecting the exhaust port and the gas introduction port avoids an upward space of the surface of the sample. The plasma processing method according to the ninth aspect is also provided so that the gas is supplied into the vacuum chamber from the gas introduction port provided at a portion not in contact with the plasma even when the plasma is generated.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. In addition, since the gas inlet is provided at the site which is not in contact with the plasma even in the step of generating the plasma, the plasma treatment can be performed without dropping particles (dust) on the sample.

According to a fifteenth aspect of the present invention, after setting the exhaust flow rate from the vacuum chamber through the exhaust port to zero or almost zero, the shortest flow path connecting the exhaust port and the gas inlet port avoids an upper space of the surface of the sample. When supplying the gas into the vacuum chamber from the gas inlet provided so as to generate the plasma, the gas is supplied into the vacuum chamber from the gas inlet provided at a portion shielded by the shielding plate from the plasma. The plasma processing method as described in the ninth aspect is provided.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. In addition, since the gas inlet is provided at a portion shielded from the plasma even in the step of generating the plasma, the plasma treatment can be performed without dropping particles (dust) to the sample.

According to a sixteenth aspect of the present invention, there is provided a plasma treatment method for introducing an impurity into a sample or a film on the surface of the sample.

Mounting the sample on the sample electrode in the vacuum chamber,

Supplying gas into the vacuum chamber from the gas inlet of the vacuum chamber while exhausting the inside of the vacuum chamber from the exhaust port of the vacuum chamber,

When the volume of the vacuum chamber is V (L: liter), the pressure in the vacuum chamber is p (Torr), and the flow rate of the gas supplied is Q (Torr · L / s), V · p / Q> 1 (s The present invention provides a plasma processing method in which a plasma is generated in the vacuum chamber by supplying high frequency power to a plasma source while introducing impurities into the sample or the film on the surface of the sample while satisfying the relation

According to this configuration, the exhaust flow rate is set to 0 or almost 0, and the high frequency power is supplied to the plasma source to generate the plasma in the vacuum chamber while the supply flow rate of the gas is set to 0 or almost 0. Plasma processing can be performed without being affected by the gas flow, thereby improving the uniformity of the treatment, including the doping concentration. In addition, since it is difficult for the reaction product to be deposited in the vicinity of the gas inlet during plasma generation, the plasma treatment can be performed without dropping particles (dust) on the sample.

According to a seventeenth aspect of the present invention, there is provided the plasma treatment method according to the sixteenth aspect, which satisfies the relationship of V · p / Q> 5 (s) when the plasma is generated.                     

According to an eighteenth aspect of the present invention, a vacuum chamber is formed, and an exhaust port for exhausting the inside of the vacuum chamber and a shortest flow path connected to the exhaust port are provided so as to avoid a space above the surface of the sample so as to supply gas into the vacuum chamber. A vacuum container having a gas inlet,

A sample electrode for mounting the sample in the vacuum chamber,

An exhaust device connected to an exhaust port of the vacuum container to exhaust the inside of the vacuum chamber;

A gas supply device connected to the gas inlet for supplying gas into the vacuum chamber;

Plasma source,

A high frequency power supply for supplying high frequency power to the plasma source;

The high frequency power is supplied to the plasma source while the exhaust flow rate from the vacuum chamber to the exhaust port is set to 0 or almost 0, and the supply flow rate of the gas from the gas inlet is set to 0 or almost 0. Thereby, the plasma processing apparatus provided with the control apparatus which generate | occur | produces a plasma in the said vacuum chamber and controls to introduce an impurity into the film | membrane of the said sample or a sample surface.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. Further, since the flow of the gas supplied from the gas inlet of the vacuum chamber into the vacuum chamber is directed toward the exhaust port while avoiding an upward space of the surface of the sample, particles (dust) do not fall on the sample. As a result, the plasma treatment can be performed to improve the uniformity of the treatment including the doping concentration.

According to a nineteenth aspect of the present invention, there is provided the plasma processing apparatus according to the eighteenth aspect, wherein the gas introduction port is provided at a portion closer to the exhaust port than the sample electrode.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. Further, since the gas inlet is provided at a portion closer to the exhaust port than the sample electrode, the plasma treatment can be performed without dropping particles (dust) on the sample.

According to a twentieth aspect of the present invention, there is provided a plasma processing apparatus according to the eighteenth aspect, wherein the gas inlet is provided at a portion below the sample electrode.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. In addition, since the gas inlet is provided at a portion below the sample electrode, plasma processing can be performed without dropping particles (dust) to the sample.

According to a twenty-first aspect of the present invention, there is provided a plasma processing apparatus according to the eighteenth aspect, wherein the gas inlet is provided to blow the gas toward the exhaust port.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. In addition, since gas is supplied from the gas inlet to the exhaust port, plasma processing can be performed without dropping particles (dust) to the sample.

According to a twenty-second aspect of the present invention, there is provided a plasma processing apparatus according to the eighteenth aspect, wherein the gas inlet is provided to blow the gas toward the exhaust apparatus.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. In addition, since gas is supplied from the gas inlet toward the exhaust apparatus, plasma processing can be performed without dropping particles (dust) to the sample.

According to a twenty third aspect of the present invention, there is provided a plasma processing apparatus according to the eighteenth aspect, wherein the gas inlet is provided at a portion which does not come into contact with the plasma when generating the plasma.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. In addition, since the gas inlet is provided at the site which is not in contact with the plasma even in the step of generating the plasma, the plasma treatment can be performed without dropping particles (dust) on the sample.

According to a twenty-fourth aspect of the present invention, there is provided a plasma processing apparatus according to the eighteenth aspect, wherein the plasma processing apparatus further comprises a shielding plate that shields the gas inlet from the plasma when the plasma is generated.

According to a twenty fifth aspect of the present invention, there is provided the plasma processing apparatus according to the eighteenth aspect, wherein the sample electrode is disposed at an uneven position from the inner wall surface of the vacuum vessel.

According to this configuration, since the exhaust flow rate is set to 0 or almost 0 and the supply flow rate of the gas is set to 0 or almost 0, high frequency power is supplied to the plasma source to generate plasma in the vacuum chamber. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. In addition, since the gas inlet is provided at a portion shielded from the plasma in the step of generating the plasma, the plasma treatment can be performed without dropping particles (dust) on the sample.

As described above, according to the plasma processing method and apparatus of the present invention, it is possible to improve the uniformity of the treatment including the doping concentration without generating particles (dust).

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings.

(First Embodiment)

EMBODIMENT OF THE INVENTION Hereinafter, 1st Embodiment of this invention is described with reference to FIGS. 1A-2.

1A and 1B show a cross-sectional view and a plan view of a plasma doping apparatus used in the first embodiment of the present invention. In FIG. 1A, while a vacuum chamber 900 is formed and a predetermined gas is introduced into the grounded vacuum vessel 1 from the gas supply device 2 through the gas inlet 11 of the vacuum vessel 1, The exhaust gas is exhausted through the exhaust port 12 of the vacuum chamber 1 by the turbo molecular pump 3 as an example of the exhaust system, and the inside of the vacuum chamber 1 is controlled to a predetermined pressure by the pressure regulating valve 4. I can keep it. As the high frequency power supply 5, for example, a high frequency power of 13.56 MHz is applied to the coil 8 provided near the upper surface of the outer side of the dielectric window 7 provided on the upper portion of the vacuum container 1 opposite the sample electrode 6. By supplying, the inductively coupled plasma can be generated in the upper space of the sample electrode 6 of the vacuum chamber 900 in the vacuum chamber 1 and the periphery thereof. The silicon substrate 9 as an example of a sample is mounted on the sample electrode 6 arranged in the vacuum container 1 via the insulator 60.

In addition, a high frequency power supply 10 for supplying high frequency power to the sample electrode 6 is provided, and the sample electrode 6 is provided such that the substrate 9 as an example of the sample has a negative potential with respect to the plasma. Can be controlled by the control device 1000.

The gas inlet 11 formed in the vacuum chamber 1 to supply gas from the gas supply device 2 to the vacuum chamber 900 is the exhaust port 12 and the gas inlet 11 of the vacuum chamber 900. In the vicinity of the exhaust port 12 so that the shortest flow path connecting the circumference avoids an upper space (the upper space of the sample electrode 6 in the first embodiment) of the surface of the silicon substrate 9 as an example of the sample. It is provided downward in the upper part of the vacuum container 1 which opposes the exhaust port 12. As shown in FIG. Therefore, the gas supplied from the gas supply device 2 is supplied to the vacuum chamber 900 in the vacuum container 1 from the gas inlet 11 provided at the portion closer to the exhaust port 12 than the sample electrode 6, The supplied gas is exhausted from the exhaust port 12 to the pump 3 without facing the upper space of the sample electrode 6. That is, all of the supplied gas finally flows into the pump 3 via the exhaust port 12.

The control device 1000 describes the gas supply device 2, the turbo molecular pump 3, the pressure regulator valve 4, the high frequency power supply 5, and the high frequency power supply 10 as described later. Motion control.

In addition, the inner wall shape of the said vacuum container 1, in other words, the shape of the vacuum chamber 900, as shown in FIG. 1B, the circumference | surroundings of the sample electrode 6 are comprised in circular shape, The periphery of the exhaust port 12 is formed in a spherical shape. However, the vacuum chamber 900 is not limited to this shape. For example, as shown in FIG. 1C, the shape of the vacuum chamber 900 of the vacuum container 1C constitutes a spherical shape around the sample electrode 6, and the periphery of the exhaust port 12 is trapezoidal. You may comprise in shape. In addition, the shape of the vacuum chamber 900 of the vacuum container 1D forms the periphery of the sample electrode 6 in large circular shape, and the periphery of the exhaust port 12 is small, as shown to FIG. 1D. You may comprise in a circular shape. In any case, the sample electrode 6 is disposed at an uneven position from the inner wall surface of the vacuum container 1.

After attaching the substrate 9 to the sample electrode 6, the gas inlet 11 is maintained while the temperature of the sample electrode 6 is maintained at 10 ° C. as an example, and the vacuum chamber 900 is exhausted from the exhaust port 12. From the vacuum chamber 900, for example, 50 sccm of helium gas, 3 sccm of the boron (B ₂ H ₆ ) gas as an example of the doping raw material gas is supplied, and the pressure regulator valve 4 is controlled to control the vacuum chamber 900. The pressure is kept at 3 Pa as an example.

Then, by stopping or nearly stopping the exhaust (in other words, setting the exhaust flow rate to zero or almost zero), by stopping or almost stopping the supply of gas (in other words, the supply flow rate of the gas is zero or almost). 0), the mixed gas of helium gas and diborane gas is filled in the vacuum chamber 900 by 3 Pa, for example.

Subsequently, by supplying high frequency power, for example, 800 W to the coil 8 as an example of the plasma source in a state where there is no or little gas flow in this manner, plasma is generated in the vacuum chamber 900 and the sample electrode is supplied to the sample electrode. For example, boron could be introduced in the vicinity of the surface of the substrate 9 by supplying high frequency power of 200 W. As shown in FIG.

FIG. 2 is a result of measuring the position of the substrate and the sheet resistance at the position when boron is doped into the silicon semiconductor substrate having a diameter of 200 mm when the x axis is taken from the left side to the right side in FIG. 1A. As is apparent from FIG. 2, the in-plane distribution of the sheet resistance is substantially uniform compared with the conventional example.

This is an example of an impurity source that is generated by generating plasma in a state where there is no gas flow, resulting from influence of pressure unevenness, flow rate unevenness, and boron partial pressure unevenness, which are shown in the prior art. It is considered that the nonuniformity of boron ion density as is reduced and the doping treatment can be performed without being affected by the gas flow.

Here, the arrangement of the gas inlet port 11 will be described.

First, for comparison, as shown in FIG. 3, the gas inlet 111 is positioned above the sample electrode 106 and above the sample electrode 106 as an example of avoiding gas flow on the sample electrode. In the case of the conventional plasma doping apparatus provided at a part far from the exhaust port 112, in the case where boron is introduced near the surface of the sample 109 by generating plasma while flowing gas, the in-plane distribution of the sheet resistance is defined as first. Although it was favorable similarly to the case of using the apparatus of FIG. 1A of 1st embodiment, particle | grains (dust) fell on the sample 109, and the yield of the element fell drastically. In Fig. 3, reference numeral 100 denotes a gas flow from the gas inlet 111 to the exhaust port 112, 101 is a vacuum vessel, 102 is a gas supply device, 103 is a turbo molecular pump, 104 is a pressure control valve, 105 is a high frequency. The power source, 107 is a dielectric window, 108 is a coil, 110 is a high frequency power source, 160 is an insulator, and 119 is a vacuum chamber.

On the other hand, when the apparatus of FIG. 1A of 1st Embodiment was used, particle | grains (dust) did not fall on the sample 9, and the yield was also high. In addition, even in the process of the conventional example which does not stop supply and exhaust of gas, particle | grains (dust) did not fall on the sample 9.

The reason for such a result is as follows. In other words, when plasma is generated while supplying gas from the gas inlet 11, the vicinity of the gas inlet 11 is locally high in pressure and high in flow rate, so that the plasma density is very low. As a result, deposition of the reaction product does not occur in the vicinity of the gas inlet 11. However, when the plasma is generated in a state where the supply of gas is stopped or almost stopped, the reaction product is also deposited in the vicinity of the gas inlet 11. When the supply of gas is resumed in the state where the reaction product is deposited near the gas inlet 11, the thin film of the reaction product deposited by the gas flow is peeled off to form particles and fall on the substrate 9.

In the apparatus of FIG. 1A, since the gas inlet 11 is positioned above the sample electrode 6 and closer to the exhaust port 12 than the sample electrode 6, the generated particles are formed in accordance with the gas flow. Since it is more likely to flow toward the exhaust port 12 side than 6) and avoids the sample electrode, it is considered that it does not fall down toward the substrate 9 side.                     

Therefore, according to the first embodiment, the plasma flow is generated in the vacuum chamber 900 by supplying high frequency power in a state in which the supply of gas is stopped or almost stopped at the same time as the exhaust is stopped or almost stopped. Plasma processing can be performed without being affected, and the uniformity of the processing including the doping concentration can be improved. In addition, since the gas inlet 11 is provided at a portion closer to the exhaust port 12 than the sample electrode 6, plasma processing is performed without dropping particles (dust) on the silicon substrate 9 as an example of the sample. Can be.

In order to verify the mechanism as described above, a description will be given with various embodiments of the arrangement of the gas inlet 11.

(2nd Embodiment)

EMBODIMENT OF THE INVENTION Hereinafter, 2nd Embodiment of this invention is described with reference to FIG.

4, sectional drawing of the plasma doping apparatus used by 2nd Embodiment of this invention is shown. In FIG. 4, while a vacuum chamber 900 is formed and a predetermined gas is introduced into the grounded vacuum container 1 from the gas supply device 2 through the gas inlet 11 of the vacuum container 1. The exhaust gas can be exhausted through the exhaust port 12 of the vacuum container 1 by the turbo molecular pump 3 as an example of the exhaust device, and the pressure regulator 4 can maintain the inside of the vacuum container 1 at a predetermined pressure. . As the high frequency power supply 5, for example, a high frequency power of 13.56 MHz is applied to the coil 8 provided near the upper surface of the outer side of the dielectric window 7 provided on the upper portion of the vacuum container 1 opposite the sample electrode 6. By supplying, the inductively coupled plasma can be generated in the upper space of the sample electrode 6 of the vacuum chamber 900 in the vacuum chamber 1 and the periphery thereof. The silicon substrate 9 as an example of a sample is mounted on the sample electrode 6 arranged in the vacuum container 1 via the insulator 60.

In addition, a high frequency power supply 10 for supplying high frequency power to the sample electrode 6 is provided, and the sample electrode 6 is provided such that the substrate 9 as an example of the sample has a negative potential with respect to the plasma. Can be controlled by the control device 1000.

The gas inlet 11 formed in the vacuum chamber 1 to supply gas from the gas supply device 2 to the vacuum chamber 900 is the exhaust port 12 and the gas inlet 11 of the vacuum chamber 900. Of the vacuum container 1 so that the shortest flow path connecting the circumference avoids an upper space (the upper space of the sample electrode 6 in the second embodiment) of the surface of the silicon substrate 9 as an example of the sample. It is a bottom surface and is provided in the site | part on the opposite side to the exhaust port 12 of the sample electrode 6 (part of the left side of the sample electrode 6 in FIG. 4). Therefore, the gas supplied from the gas supply device 2 is a portion below the sample electrode 6, specifically, a bottom surface of the vacuum container 1 and a portion opposite to the exhaust port 12 of the sample electrode 6. The introduced gas is introduced into the vacuum chamber 900 in the vacuum chamber 1 from the gas inlet 11 provided at the upper side of the sample electrode 6 without facing the upper space of the sample electrode 6. It passes to the exhaust port 12 and is exhausted from the exhaust port 12 to the pump 3.

The controller 1000 operates and controls the gas supply device 2, the turbo molecular pump 3, the pressure regulator valve 4, the high frequency power supply 5, and the high frequency power supply 10 as follows. .

After attaching the substrate 9 to the sample electrode 6, the gas inlet 11 is maintained while the temperature of the sample electrode 6 is maintained at 10 ° C., for example, and the vacuum chamber 900 is exhausted from the exhaust port 12. In the vacuum chamber 900, for example, 50 sccm of helium gas, 3 sccm of the boron (B ₂ H ₆ ) gas as an example of the doping source gas, and the pressure regulating valve 4 are controlled to control the pressure in the vacuum chamber 900. The pressure is maintained at 3 Pa, for example.

Then, by stopping or nearly stopping the exhaust (in other words, setting the exhaust flow rate to zero or almost zero), by stopping or almost stopping the supply of gas (in other words, the supply flow rate of the gas is zero or almost). By setting it to 0), there is no or almost no gas flow, that is, the vacuum chamber 900 is filled with a mixed gas of helium gas and diborane gas, for example, 3 Pa.

Subsequently, by supplying high frequency power, for example, 800 W to the coil 8 as an example of the plasma source in a state where there is no or little gas flow in this manner, plasma is generated in the vacuum chamber 900 and the sample electrode is supplied to the sample electrode. For example, boron could be introduced in the vicinity of the surface of the substrate 9 by supplying high frequency power of 200 W. As shown in FIG.

Also in this case, the in-plane distribution of sheet resistance was remarkably uniform compared with the conventional example. This is an example of an impurity source that is generated by generating plasma in a state where there is no or little gas flow, resulting from influences of pressure variations, flow velocity variations, and boron partial pressure variations. It is considered that the nonuniformity of the boron ion density was reduced and the doping treatment could be performed without being affected by the gas flow.

In addition, since the plasma was generated while the gas supply was stopped or almost stopped, the reaction product was deposited in the vicinity of the gas inlet 11. However, in the apparatus of FIG. 4, the gas inlet 11 is connected to the sample electrode. Since it provided in the site | region (region of low plasma density) lower than (6), the quantity of reaction products to deposit | accumulate | reduced was drastically small compared with the conventional example. As a result, the particles did not fall on the substrate 9.

Therefore, according to the second embodiment, since the exhaust gas is stopped or almost stopped and the high frequency power is supplied at the same time as the supply of the gas is stopped or almost stopped, the plasma is generated in the vacuum chamber 900. Plasma processing can be performed without being influenced by the flow, thereby improving the uniformity of the processing, including the doping concentration. In addition, since the gas inlet 11 is provided at a portion below the sample electrode 6, plasma processing can be performed without falling particles (dust) on the silicon substrate 9 as an example of the sample.

(Third Embodiment)

EMBODIMENT OF THE INVENTION Hereinafter, 3rd Embodiment of this invention is described with reference to FIG.

5 is a cross-sectional view of the plasma doping apparatus used in the third embodiment of the present invention. In FIG. 5, while the vacuum chamber 900 is formed and a predetermined gas is introduced into the grounded vacuum container 1 from the gas supply device 2 through the gas inlet 11 of the vacuum container 1. The exhaust gas can be exhausted through the exhaust port 12 of the vacuum container 1 by the turbo molecular pump 3 as an example of the exhaust device, and the pressure regulator 4 can maintain the inside of the vacuum container 1 at a predetermined pressure. . As the high-frequency power supply 5, for example, by supplying high-frequency power of 13.56 MHz to the coil 8 provided near the dielectric window 7 provided on the upper portion of the vacuum container 1 opposite the sample electrode 6, The inductively coupled plasma can be generated in an upper space of the sample electrode 6 of the vacuum chamber 900 in the vacuum chamber 1 and the periphery thereof. The silicon substrate 9 as an example of a sample is mounted on the sample electrode 6 arranged in the vacuum container 1 via the insulator 60.

In addition, a high frequency power supply 10 for supplying high frequency power to the sample electrode 6 is provided, and the potential of the sample electrode 6 is controlled so that the substrate 9 as an example of the sample has a negative potential with respect to the plasma. It can be controlled by the apparatus 1000.

The gas inlet 11 formed in the vacuum chamber 1 to supply gas from the gas supply device 2 to the vacuum chamber 900 is the exhaust port 12 and the gas inlet 11 of the vacuum chamber 900. In the vicinity of the exhaust port 12 so that the shortest flow path connecting the circumference avoids an upper space (the upper space of the sample electrode 6 in the third embodiment) of the surface of the silicon substrate 9 as an example of the sample. Is provided toward the exhaust port 12 in the vacuum container 1. Therefore, the gas supplied from the gas supply device 2 is introduced into the vacuum chamber 900 in the vacuum container 1 from the gas inlet 11 provided near the exhaust port 12 toward the exhaust port 12, and is supplied. The gas is exhausted from the exhaust port 12 to the pump 3 without facing the space above the sample electrode 6.

The controller 1000 operates and controls the gas supply device 2, the turbo molecular pump 3, the pressure regulator valve 4, the high frequency power supply 5, and the high frequency power supply 10 as follows. .

After attaching the substrate 9 to the sample electrode 6, the gas inlet 11 is maintained while the temperature of the sample electrode 6 is maintained at 10 ° C., for example, and the vacuum chamber 900 is exhausted from the exhaust port 12. In the vacuum chamber 900, for example, 50 sccm of helium gas, 3 sccm of the boron (B ₂ H ₆ ) gas as an example of the doping source gas, and the pressure regulating valve 4 are controlled to control the pressure in the vacuum chamber 900. The pressure is maintained at 3 Pa, for example.

Then, by stopping or nearly stopping the exhaust (in other words, setting the exhaust flow rate to zero or almost zero), by stopping or almost stopping the supply of gas (in other words, the supply flow rate of the gas is zero or almost). By setting it to 0), there is no or almost no gas flow, that is, the vacuum chamber 900 is filled with a mixed gas of helium gas and diborane gas, for example, 3 Pa.

Subsequently, by supplying a high frequency power, for example, 800 W to the coil 8 as an example of the plasma source in a state where there is no or little gas flow in this manner, plasma is generated in the vacuum chamber 900 and the sample electrode is applied to the sample electrode. For example, boron could be introduced in the vicinity of the surface of the substrate 9 by supplying high frequency power of 200 W. As shown in FIG.

Also in this case, the in-plane distribution of sheet resistance was remarkably uniform compared with the conventional example. This is an example of an impurity source that is generated by generating plasma in a state where there is no or little gas flow, resulting from influences of pressure variations, flow velocity variations, and boron partial pressure variations. It is considered that the nonuniformity of the boron ion density was reduced and the doping treatment could be performed without being affected by the gas flow.

In addition, since the plasma was generated in a state in which the gas supply was stopped or almost stopped, the reaction product was deposited in the vicinity of the gas inlet 11, and the reaction deposited by the gas flow when the gas supply was resumed. The thin film of product is peeled off. However, in the apparatus of FIG. 5, since the gas inlet 11 was provided toward the exhaust port 12, the particles did not fall on the substrate 9. Further, even in the step of generating the plasma, the gas inlet 11 is disposed at a portion that does not contact the plasma, so that when the plasma is generated, the reaction product hardly accumulates in the vicinity of the gas inlet 11 and exhausts. Particles to be reduced are also reduced, and more stable plasma doping treatment can be performed.

Therefore, according to the third embodiment, while the exhaust flow rate is set to 0 (stop) or almost 0 (almost stop), and the supply flow rate of the gas is set to 0 (stop) or almost 0 (almost stop), Since high-frequency power is supplied to the coil 8 as an example of the plasma source to generate plasma in the vacuum chamber 900, the plasma processing can be performed without being affected by the gas flow, so that the uniformity of the processing including the doping concentration can be performed. You can improve your sex. Moreover, since gas is supplied from the gas inlet 11 toward the exhaust port 12, plasma processing can be performed without particle (dust) falling to the silicon substrate 9 as an example of a sample.

(Fourth Embodiment)

EMBODIMENT OF THE INVENTION Hereinafter, 4th Embodiment of this invention is described with reference to FIG.

6, the cross section of the plasma doping apparatus used by 4th Embodiment of this invention is shown. In FIG. 6, while the vacuum chamber 900 is formed and a predetermined gas is introduced into the grounded vacuum container 1 from the gas supply device 2 through the gas inlet 11 of the vacuum container 1. The exhaust gas can be exhausted through the exhaust port 12 of the vacuum container 1 by the turbo molecular pump 3 as an example of the exhaust device, and the pressure regulator 4 can maintain the inside of the vacuum container 1 at a predetermined pressure. . As the high frequency power supply 5, for example, a high frequency power of 13.56 MHz is applied to the coil 8 provided near the upper surface of the outer side of the dielectric window 7 provided on the upper portion of the vacuum container 1 opposite the sample electrode 6. By supplying, the inductively coupled plasma can be generated in the upper space of the sample electrode 6 of the vacuum chamber 900 in the vacuum chamber 1 and the periphery thereof. The silicon substrate 9 as an example of a sample is mounted on the sample electrode 6 arranged in the vacuum container 1 via the insulator 60.

In addition, a high frequency power supply 10 for supplying high frequency power to the sample electrode 6 is provided, and the potential of the sample electrode 6 is controlled so that the substrate 9 as an example of the sample has a negative potential with respect to the plasma. It can be controlled by the apparatus 1000.

The gas inlet 11 formed in the vacuum chamber 1 to supply gas from the gas supply device 2 to the vacuum chamber 900 is the exhaust port 12 and the gas inlet 11 of the vacuum chamber 900. In the vicinity of the exhaust port 12 so that the shortest flow path connecting the circumference avoids an upper space (the upper space of the sample electrode 6 in the fourth embodiment) of the surface of the silicon substrate 9 as an example of the sample. Moreover, it is provided toward the exhaust port 12 at the position which opposes the exhaust port 12 of the upper part of the vacuum container 1 which opposes the exhaust port 12. Therefore, the gas supplied from the gas supply device 2 is introduced into the vacuum container 1 from the gas inlet 11 provided in the vicinity of the exhaust port 12 toward the pump 3, and the supplied gas is a sample. The exhaust gas is exhausted from the exhaust port 12 to the pump 3 without facing the upper space of the electrode 6.

The controller 1000 operates and controls the gas supply device 2, the turbo molecular pump 3, the pressure regulator valve 4, the high frequency power supply 5, and the high frequency power supply 10 as follows. .

After attaching the substrate 9 to the sample electrode 6, the gas inlet 11 is maintained while the temperature of the sample electrode 6 is maintained at 10 ° C., for example, and the vacuum chamber 900 is exhausted from the exhaust port 12. In the vacuum chamber 900, for example, 50 sccm of helium gas, 3 sccm of the boron (B ₂ H ₆ ) gas as an example of the doping source gas, and the pressure regulating valve 4 are controlled to control the pressure in the vacuum chamber 900. The pressure is maintained at 3 Pa, for example.

Then, by stopping or nearly stopping the exhaust (in other words, setting the exhaust flow rate to zero or almost zero), by stopping or almost stopping the supply of gas (in other words, the supply flow rate of the gas is zero or almost). By setting it to 0), there is no or almost no gas flow, that is, the vacuum chamber 900 is filled with a mixed gas of helium gas and diborane gas, for example, 3 Pa.

Subsequently, by supplying high frequency power, for example, 800 W to the coil 8 as an example of the plasma source in a state where there is no or little gas flow in this manner, plasma is generated in the vacuum chamber 900 and the sample electrode is supplied to the sample electrode. For example, boron could be introduced in the vicinity of the surface of the substrate 9 by supplying high frequency power of 200 W. As shown in FIG.

Also in this case, the in-plane distribution of sheet resistance was remarkably uniform compared with the conventional example. This is an example of an impurity source that is generated by generating plasma in a state where there is no or little gas flow, and is caused by the influence of pressure unevenness, flow rate unevenness, and boron partial pressure unevenness, which are shown in the prior art. It is considered that the nonuniformity of boron ion density as is reduced and the doping treatment can be performed without being affected by the gas flow.

In addition, since the plasma was generated while the gas supply was stopped or almost stopped, the reaction product was deposited in the vicinity of the gas inlet 11, and the reaction product deposited by the gas flow when the gas supply was resumed. The thin film is peeled off. However, in the apparatus of FIG. 6, since the gas inlet 11 was provided toward the pump 3, the particles did not fall on the substrate 9. Further, even in the step of generating the plasma, the gas inlet 11 is disposed at a portion that does not contact the plasma, so that when the plasma is generated, the reaction product hardly accumulates in the vicinity of the gas inlet 11 and exhausts. Particles to be reduced are also reduced, and more stable plasma doping treatment can be performed.

Therefore, according to the fourth embodiment, the plasma is discharged in a state in which the exhaust flow rate is set to 0 (stop) or almost 0 (almost stop) and the supply flow rate of the gas is set to 0 (stop) or almost 0 (almost stop). Since a high frequency electric power was supplied to the coil 8 as an example of a circle to generate a plasma in the vacuum chamber 900, the plasma processing can be performed without being affected by the gas flow, so that the uniformity of the processing including the doping concentration can be performed. It will be possible to improve. Further, since gas is supplied from the gas inlet 11 to the turbomolecular pump 3 as an example of the exhaust device, plasma processing is executed without dropping particles (dust) to the silicon substrate 9 as an example of the sample. Can be.

(5th Embodiment)

EMBODIMENT OF THE INVENTION Hereinafter, 5th Embodiment of this invention is described with reference to FIG.

7 is a sectional view of the plasma doping apparatus used in the fifth embodiment of the present invention. In Fig. 7, a vacuum chamber 900 is formed and a predetermined gas is introduced into the grounded vacuum vessel 1 from the gas supply device 2 through the gas inlet 11 of the vacuum vessel 1. The exhaust gas can be exhausted through the exhaust port 12 of the vacuum container 1 by the turbo molecular pump 3 as an example of the exhaust device, and the pressure regulator 4 can maintain the inside of the vacuum container 1 at a predetermined pressure. . As the high frequency power supply 5, for example, a high frequency power of 13.56 MHz is applied to the coil 8 provided near the upper surface of the outer side of the dielectric window 7 provided on the upper portion of the vacuum container 1 opposite the sample electrode 6. By supplying, the inductively coupled plasma can be generated in the upper space of the sample electrode 6 of the vacuum chamber 900 in the vacuum chamber 1 and the periphery thereof. The silicon substrate 9 as an example of a sample is mounted on the sample electrode 6 arranged in the vacuum container 1 via the insulator 60.

In addition, a high frequency power supply 10 for supplying high frequency power to the sample electrode 6 is provided, and the potential of the sample electrode 6 is controlled so that the substrate 9 as an example of the sample has a negative potential with respect to the plasma. It can be controlled by the apparatus 1000.

The gas inlet 11 formed in the vacuum chamber 1 to supply gas from the gas supply device 2 to the vacuum chamber 900 is the exhaust port 12 and the gas inlet 11 of the vacuum chamber 900. Of the sample electrodes 6 so that the shortest flow path that connects the circumference avoids an upper space of the surface of the silicon substrate 9 as an example of the sample (the upper space of the sample electrode 6 in the fifth embodiment). It is provided in the transverse direction in the side part (the side part of the left side of the sample electrode 6 in FIG. 4) of the vacuum container 1 on the opposite side to the exhaust port 12, and the gas inlet 11 The shielding plate 13 as an example of the shielding member which shields the opening of (circle) to the sample electrode 6 side is provided.

The shielding plate 13 is made of a metal material having a shielding function and not reacting with the plasma, grounded together with the vacuum container 1, and protruding inwardly from the inner wall of the side portion of the vacuum container 1. It is then bent in the downward direction, and is composed of a substrate having a cross-section having an L shape. As the shielding plate 13, the gas is guided downward along the inner surface facing the gas inlet 11. In order to further ensure the guidance of this gas, the inner surface facing the gas inlet 11 is provided with a recess 13a as shown in FIGS. 7B to 7D, and is supplied from the gas inlet 11. The gas is guided downwardly around the sample electrode 6 by the recessed portion 13a without facing the side of the shield plate 13. As a material of the shielding plate 13, besides metal, insulating materials, such as ceramics, can also be used.

Therefore, the gas supplied from the gas supply device 2 is a vacuum container toward the pump 3 from the gas inlet 11 provided at the site shielded by the shielding plate 13 from the plasma in the step of generating the plasma. The gas introduced into (1) and supplied is guided so as to flow around the lower side of the sample electrode 6 by the shielding plate 13 without facing the space toward the upper direction of the sample electrode 6. 12 is exhausted from the pump 3.

The control device 1000 describes the gas supply device 2, the turbo molecular pump 3, the pressure regulator valve 4, the high frequency power supply 5, and the high frequency power supply 10 as described later. Motion control.

Moreover, as another example of the said shielding plate 13, 13A of shielding plates which do not have the recessed part 13a may be sufficient, as shown to FIG. 7E-7G.

After attaching the substrate 9 to the sample electrode 6, the gas inlet 11 is maintained while the temperature of the sample electrode 6 is maintained at 10 ° C., for example, and the vacuum chamber 900 is exhausted from the exhaust port 12. In the vacuum chamber 900, for example, 50 sccm of helium gas, 3 sccm of the boron (B ₂ H ₆ ) gas as an example of the doping source gas, and the pressure regulating valve 4 are controlled to control the pressure in the vacuum chamber 900. The pressure is maintained at 3 Pa, for example.

Then, by stopping or nearly stopping the exhaust (in other words, setting the exhaust flow rate to zero or almost zero), by stopping or almost stopping the supply of gas (in other words, the supply flow rate of the gas is zero or almost). By setting it to 0), there is no or almost no gas flow, that is, the vacuum chamber 900 is filled with a mixed gas of helium gas and diborane gas, for example, 3 Pa.

Subsequently, by supplying high frequency power, for example, 800 W to the coil 8 as an example of the plasma source in a state where there is no or little gas flow in this manner, plasma is generated in the vacuum chamber 900 and the sample electrode is supplied to the sample electrode. For example, boron could be introduced in the vicinity of the surface of the substrate 9 by supplying high frequency power of 200 W. As shown in FIG.

Also in this case, the in-plane distribution of sheet resistance was remarkably uniform compared with the conventional example. This is an example of an impurity source that is generated by generating plasma in a state where there is no or little gas flow, resulting from influences of pressure variations, flow velocity variations, and boron partial pressure variations. It is considered that the nonuniformity of the boron ion density was reduced and the doping treatment could be performed without being affected by the gas flow.

In addition, since the plasma was generated while the gas supply was stopped or almost stopped, the reaction product was deposited in the vicinity of the gas inlet 11, and the reaction product deposited by the gas flow when the gas supply was resumed. The thin film is peeled off.

However, in the apparatus of FIG. 7, the gas inlet 11 is provided at a portion shielded by the shielding plate 13 from the plasma generated in the step of generating the plasma, so that when the plasma is generated, the gas inlet 11 The reaction product hardly deposited in the vicinity of), the particles were drastically reduced, and more stable plasma doping treatment could be performed.

Therefore, according to the fifth embodiment, the plasma is discharged in a state in which the exhaust flow rate is 0 (stop) or almost 0 (almost stop) and the supply flow rate of the gas is 0 (stop) or almost 0 (almost stop). Since a high frequency electric power was supplied to the coil 8 as an example of a circle to generate a plasma in the vacuum chamber 900, the plasma processing can be performed without being affected by the gas flow, so that the uniformity of the processing including the doping concentration can be performed. It will be possible to improve. In addition, since the gas inlet 11 is provided at a portion which is not in contact with the plasma even in the step of generating the plasma, plasma processing is performed without dropping particles (dust) on the silicon substrate 9 as an example of the sample. You can run

8, the structure of the plasma doping apparatus used by the modification of 5th Embodiment of this invention is shown. In the plasma doping apparatus of this modification of FIG. 8, not only one gas inlet 11 but also in other words, not only the side part of the vacuum container 1 on the opposite side to the exhaust port 12 of the sample electrode 6, On the periphery of the sample electrode 6, a plurality of places are provided in the transverse direction at every 90 degree intervals (for example, every 180 degree interval in FIG. 4, that is, the left side and the right side of the sample electrode 6). Moreover, the shielding plate 13 is also provided, respectively. In this case, the plurality of gas inlet ports 11 communicate with each other by the gas inlet passage B formed through the side portion of the vacuum container 1, so that the gas supply, the gas supply stop or almost stop can be simultaneously performed. It is. In this way, the gas is simultaneously supplied from the plurality of gas inlets 11 to the periphery of the sample electrode 6 and guided downwardly around the sample electrode 6 by the shielding plate 13, respectively, 12), the gas supply can be made more efficient.

In each of the first to fifth embodiments of the present invention described above, the gas is enclosed in the vacuum container 1 at a predetermined pressure by stopping or almost stopping the supply of gas at almost the same time as stopping or almost stopping the exhaust. Although the case where there is no or almost no gas flow is illustrated, when the stop or nearly stop of the exhaust gas and the stop or near stop of the gas supply are accurately and accurately reproduced, the predetermined time has elapsed after stopping or almost stopping the exhaust gas. By stopping or almost stopping the gas supply afterwards, it is possible to bring the gas into or without the flow of gas. On the contrary, the gas supply may be stopped or almost stopped after the predetermined time has elapsed after the supply of the gas has been stopped or almost stopped.

Alternatively, the supply of gas and the stop of the exhaust or the almost stop are not performed at the same time, and after the exhaust of the vacuum vessel is stopped or almost stopped, a predetermined time from the gas inlet into the vacuum vessel, or the pressure in the vacuum vessel is a predetermined pressure. The gas is supplied until the gas is reached, and then the supply of the gas is stopped or almost stopped to make the gas flow free or almost free, and then a high frequency electric power is supplied to the plasma source to generate plasma in the vacuum vessel to doping. It is also possible to execute the process.

FIG. 9: is a figure which shows the condition table in a 38-liter vacuum chamber as a specific example of the plasma doping process performed with the plasma doping apparatus used in 1st, 2nd, 3rd, 4th and 5th embodiment of the present invention.

In this example, in the gas supply and exhaust process of Step No. 1, the pressure is 3 Pa, the He flow rate is 50 sccm, the B ₂ H ₆ flow rate is 3 sccm, (V · p / Q) is 1.3 s, and the exhaust gas is turned on ( ON), high frequency power (ICP / BIAS) is 0/0 (W). Subsequently, in the gas supply stop and the exhaust stop step of Step No. 2, the pressure is 3 Pa, the He flow rate is 0 sccm, the B ₂ H ₆ flow rate is 0 sccm, (V · p / Q) cannot be calculated, and the exhaust is turned off. (OFF), high frequency power (ICP / BIAS) is 0/0 (W). In the plasma generation (plasma doping) process of Step No. 3, the pressure is 3 Pa, the He flow rate is 0 sccm, the B ₂ H ₆ flow rate is 0 sccm, (V · p / Q) cannot be calculated, and the exhaust is turned off (OFF). ), High frequency power (ICP / BIAS) is 800/200 (W).

Fig. 10 is a specific example of the plasma doping apparatus used in the fifth embodiment of the present invention. First, the exhaust gas is stopped and the gas supply is stopped at the same time as 4 Pa. Drawing.

In this example, in the gas supply and exhaust process of Step No. 1, the pressure is 3 Pa, the He flow rate is 100 sccm, the B ₂ H ₆ flow rate is 6 sccm, (Vp / Q) is 0.64 s, and the exhaust gas is turned on ( ON), high frequency power (ICP / BIAS) is 0/0 (W). Subsequently, in the gas supply and exhaust stop process of step No. 2, the pressure is 3 Pa, the He flow rate is 100 sccm, the B ₂ H ₆ flow rate is 6 sccm, (V · p / Q) cannot be calculated, and the exhaust is turned off ( OFF), high frequency power (ICP / BIAS) is 0/0 (W). In the gas supply stop and exhaust stop processes of step No. 3, the pressure is 4 Pa, the He flow rate is O sccm, the B ₂ H ₆ flow rate is O sccm, (V · p / Q) cannot be calculated, and the exhaust is turned off (OFF). ), The high frequency power (ICP / BIAS) is 0/0 (W). In the plasma generation (plasma doping) process of Step No. 4, the pressure is 4 Pa, the He flow rate is O sccm, the B ₂ H ₆ flow rate is O sccm, (V · p / Q) cannot be calculated, and the exhaust is turned off, Power (ICP / BIAS) is 800/200 (W).

Fig. 11 is another specific example of the plasma doping apparatus used in the fifth embodiment of the present invention. First, a condition table in a 38-liter vacuum chamber when gas supply is first stopped and exhaust is stopped at the same time as 2 Pa is shown. It is a drawing of.

In this example, in the gas supply and exhaust process of Step No. 1, the pressure is 3 Pa, the He flow rate is 198 sccm, the B ₂ H ₆ flow rate is 2 sccm, (Vp / Q) is 0.34 s, and the exhaust is turned on ( ON), high frequency power (ICP / BIAS) is 0/0 (W). Subsequently, in the gas supply stop and exhaust process of step No. 2, the pressure is 3 Pa, the He flow rate is O sccm, the B ₂ H ₆ flow rate is O sccm, (V · p / Q) cannot be calculated, and the exhaust gas is turned on ( ON), high frequency power (ICP / BIAS) is 0/0 (W). In the gas supply stop and exhaust stop processes of step No. 3, the pressure is 2 Pa, the He flow rate is O sccm, the B ₂ H ₆ flow rate is O sccm, (V · p / Q) cannot be calculated, and the exhaust is turned off and high frequency. Power (ICP / BIAS) is 0/0 (W). In the plasma generation (plasma doping) process of Step No. 4, the pressure is 2 Pa, the He flow rate is O sccm, the B ₂ H ₆ flow rate is O sccm, (V · p / Q) cannot be calculated, and the exhaust is turned off, Power (ICP / BIAS) is 800/200 (W).

(Sixth Embodiment)

EMBODIMENT OF THE INVENTION Hereinafter, 6th Embodiment of this invention is described. In the sixth embodiment of the present invention, a plasma processing apparatus similar to FIG. 13 used in the conventional example is used.

FIG. 12A shows a schematic configuration of a plasma processing apparatus similar to the conventional plasma processing apparatus of FIG. 13. In FIG. 12A, a sample electrode 1206 for mounting a sample 1209 made of a silicon substrate is provided in the vacuum chamber 1201. A gas supply device 1202 for supplying a doping source gas containing an element required in the vacuum chamber 1201, for example, B ₂ H _6, and a pump 1203 for reducing the pressure inside the vacuum chamber 1201 are provided. The inside of the vacuum chamber 1201 can be maintained at a predetermined pressure. Microwaves are emitted from the microwave waveguide 1219 into the vacuum chamber 1201 through the quartz plate 1207 serving as the dielectric window. Due to the interaction between the microwaves and the direct current magnetic field formed from the electromagnet 1214, a magnetic field microwave plasma (electron cyclotron resonance plasma) 1220 is formed in the vacuum chamber 1201. The high frequency power supply 1210 is connected to the sample electrode 1206 through a capacitor 1221 so that the potential of the sample electrode 1206 can be controlled. In addition, the gas supplied from the gas supply device 1202 is introduced into the vacuum chamber 1201 from the gas inlet 1211 and is exhausted from the exhaust port 1212 to the pump 1203.

In the plasma processing apparatus having such a configuration, the doping source gas introduced from the gas inlet 1211, for example, B ₂ H _6, is converted into plasma by the plasma generating means composed of the microwave waveguide 1219 and the electromagnet 1214. Boron ions in the plasma 1220 are introduced into the surface of the sample 1209 by the high frequency power supply 1210.

After the metal wiring layer is formed on the sample 1209 into which impurities are introduced in this manner, a thin oxide film is formed on the metal wiring layer in a predetermined oxidizing atmosphere, and thereafter, the gate electrode is formed on the sample 1209 using a CVD apparatus or the like. In this case, for example, a MOS transistor can be formed.

After attaching the substrate 1209 to the sample electrode 1206, the gas inlet 1211 is maintained while the temperature of the sample electrode 1206 is maintained at 10 ° C. as an example, and the inside of the vacuum chamber 1201 is exhausted from the exhaust port 1212. 7 sccm of helium gas and 3 sccm of zibolan (B ₂ H ₆ ) gas as an example of a doping raw material gas are supplied into the vacuum chamber 1201, and the pressure control valve 1230 is controlled to control the pressure in the vacuum chamber 1201. As an example of the plasma source, microwaves are radiated from the microwave waveguide 1219 into the vacuum chamber 1201 through the quartz plate 1207 serving as the dielectric window, and the microwaves and the electromagnet 1214 are maintained as 3 Pa, for example. Due to the interaction of the direct-current magnetic field formed in FIG. 1, the magnetic field microwave plasma (electron cyclotron resonance plasma) 1220 is generated in the vacuum chamber 1201, and 200 W of high frequency power is supplied to the sample electrode 1206 as an example. Thus, boron is used as a substrate (1 209) was introduced near the surface.

At this time, the in-plane distribution of sheet resistance was remarkably uniform compared with the conventional example. This is because there is a little gas flow, but since the gas supply amount is very small (it can be regarded as a stationary state in which the gas supply amount is almost zero), the variation in pressure, the flow rate, the boron partial pressure, and the like, which are conventional examples, are affected. It is considered that the nonuniformity of boron ion density as an example of the impurity source, which is generated by giving, can be reduced, and the doping treatment can be carried out under a small influence of the gas flow.

The average residence time of the gas in the vacuum chamber 900 under these conditions was calculated. The residence time is V · p / Q when the volume of the vacuum chamber 900 is V (L: liter), the pressure in the vacuum chamber 900 is p (Torr), and the gas flow rate is Q (Torr · L / s). (Unit is expressed as s). Under this condition, V = 38 (L), p = 3 (Pa) = 0.023 (Torr), Q = 7 + 3 (sccm) = 10 (sccm) = 0.13 (Torr · L / s), so that the residence time: V · p / Q = 6.7 (s).

Therefore, as a result of evaluating the in-plane distribution of the sheet resistance under various conditions, the in-plane distribution of the sheet resistance became less than ± 10% when satisfying the relation of V · p / Q> 1 (s), resulting in good results. I knew to indicate. In the plasma generation step, when the relation of V · p / Q> 5 (s) is satisfied, the in-plane distribution of the sheet resistance is less than ± 5%, which shows better results.

From the viewpoint of uniformity, the larger V · p / Q is better, the larger one may be disadvantageous from another viewpoint. In other words, the increase in V causes an increase in the price of the vacuum vessel and the device installation area. In addition to increasing p and decreasing Q, the time taken to reach a predetermined pressure is increased, and there is a disadvantage in that mixing of impurities (constituent elements such as vacuum containers, etc.) other than the required impurities is increased. Therefore, it is preferable that V * p / Q is about 20 s or less.

According to this configuration, the plasma flow rate is maintained in a state in which the exhaust flow rate is made substantially zero (almost stop) and the supply flow rate of the gas is made substantially zero (almost stop) by setting V · p / Q to approximately 20 s or less. Since the plasma 8 is generated in the vacuum chamber 900 by supplying high frequency power to the coil 8 as an example, the plasma processing can be performed without being affected by the gas flow, thereby improving the uniformity of the processing including the doping concentration. You can do it. In addition, since the supply of the gas is not stopped and the reaction product is difficult to deposit in the vicinity of the gas inlet 11 during plasma generation (in other words, plasma is generated while supplying the gas from the gas inlet 11). Since the pressure in the vicinity of the gas inlet 11 is locally high and the flow velocity is high, the plasma density is very low, and as a result, deposition of the reaction product in the vicinity of the gas inlet 11 is unlikely to occur). Plasma processing can be performed without particle (dust) falling on the silicon substrate 9 as an example.

12B is a diagram showing a condition table in a 38-liter vacuum chamber as a specific example of the plasma doping process performed by the plasma doping apparatus used in the sixth embodiment of the present invention.

In this example, in the gas supply and exhaust process of Step No. 1, the pressure is 3 Pa, the He flow rate is 7 sccm, the B ₂ H ₆ flow rate is 3 sccm, (Vp / Q) is 6.7 s, and the exhaust gas is turned on ( ON), high frequency power (ICP / BIAS) is 0/0 (W). Subsequently, in the gas supply and exhaust process of Step No. 2, the pressure is 3 Pa, the He flow rate is 7 sccm, the B ₂ H ₆ flow rate is 3 sccm, (V · p / Q) is 6.7 s, and the exhaust is ON. The high frequency power (ICP / BIAS) is 800/200 (W).

In the various embodiments of the present invention described above, only some of the various modifications are exemplified with respect to the shape of the vacuum container (vacuum chamber), the method and arrangement of the plasma source, etc. in the application range of the present invention. In the application of the present invention, it goes without saying that various modifications can be considered in addition to those exemplified here.

For example, the coil 8 may be planar, or a helicon wave plasma source, a magnetic neutral loop plasma source, and a magnetic field microwave plasma source (electron cyclotron resonance plasma source) may be used. You may use a parallel plate type plasma source.

Inert gases other than helium may also be used, and at least one of neon, argon, krypton or xenon (xenon) may be used. Such an inert gas has an advantage that the adverse effect on the sample is smaller than that of other gases.

Moreover, although the case where the sample is a semiconductor substrate comprised from silicon was illustrated, when this invention processes the sample of other various materials, this invention can be applied.

Moreover, although the case where an impurity is boron was illustrated, this invention is effective when a sample is a semiconductor substrate comprised from silicon, especially when an impurity is arsenic, phosphorus, boron, aluminum, or antimony. This is because a shallow junction can be formed in the transistor portion.

Moreover, this invention is effective when a doping concentration is low concentration, and it is especially effective as a plasma doping method which aims at 1 * 10 <^11> / cm <^2> -1 * 10 <^17> / cm <^2> . Moreover, especially a plasma doping method which aims at 1 * 10 <^11> / cm <^2> -1 * 10 <^14> / cm <^2> , a special effect is shown. If the doping concentration is greater than 1 × 10 ¹⁷ / cm ² has, with respect to possible with conventional ion implantation, the device is by the conventional process in which a doping concentration is required to 1 × 10 ¹⁷ / cm ² or less could not cope, According to this invention, it becomes possible to respond.

In addition, although the case where the pressure in the vacuum chamber in the step of generating a plasma was 3 Pa was illustrated, it is preferable that the pressure in the vacuum container in the step of generating a plasma is 0.01 Pa-5 Pa. If the pressure is too low (that is, if the pressure is less than 0.01 Pa), there is a disadvantage that the sealing accuracy of the gas is deteriorated. Conversely, if the pressure is too high (that is, if the pressure exceeds 5 Pa), it becomes difficult to generate a sufficient self bias voltage to the substrate. More preferably, the pressure in the vacuum vessel in the step of generating the plasma is preferably 0.1 to 1 Pa. In the range of 0.1 to 1 Pa, the sealing accuracy is further increased, and the controllability of the self bias is good.

In addition, although the case where the gas supplied in a vacuum container is a gas containing a doping raw material was illustrated, this invention is effective also when the gas supplied in a vacuum container does not contain a doping raw material and produces a doping raw material from solid impurities. Do.

In addition, although plasma doping is illustrated, the present invention is also applicable to other plasma treatments such as dry etching, ashing, plasma CVD, and the like.

Furthermore, by combining appropriately any of the above embodiments, it is possible to achieve the effects each has.

The plasma processing method and apparatus of the present invention can improve the uniformity of treatment, including doping concentration, without generating particles (dust), thereby producing thin film transistors used in liquid crystals and the like, including impurity doping processes for semiconductors. The present invention can also be applied to applications such as surface modification of various materials. The present invention is also applicable to other plasma treatments such as dry etching, ashing, plasma CVD, and the like.

Claims (25)

In the plasma processing method for introducing an impurity into a sample or a film on the surface of the sample, Mounting the sample on the sample electrode in the vacuum chamber, While exhausting the inside of the vacuum chamber from the exhaust port of the vacuum chamber, gas is supplied into the vacuum chamber from a gas inlet provided in a portion closer to the exhaust port of the vacuum chamber than the sample electrode. The exhaust flow rate from the inside of the vacuum chamber to the exhaust port is set to 0, and the supply flow rate of the gas from the gas inlet is set to 0. A plasma processing method comprising generating plasma in the vacuum chamber by supplying high frequency power to a plasma source to introduce impurities into the sample or the film on the surface of the sample. In the plasma processing method for introducing impurities into a sample or a film on the surface of the sample, Mounting the sample on the sample electrode in the vacuum chamber, While exhausting the inside of the vacuum chamber from the exhaust port of the vacuum chamber, gas is supplied into the vacuum chamber from the gas introduction port provided so that the shortest flow path connecting the exhaust port and the gas inlet port of the vacuum chamber avoids the space above the surface of the sample. Thus, the flow of the gas supplied from the gas inlet of the vacuum chamber into the vacuum chamber is directed toward the exhaust port while avoiding an upward space on the surface of the sample. The exhaust flow rate from the inside of the vacuum chamber to the exhaust port is set to 0, and the supply flow rate of the gas from the gas inlet is set to 0. And generating impurities into the vacuum chamber by supplying high frequency power to a plasma source to introduce impurities into the sample or the film on the surface of the sample. The said shortest flow path which connects the said exhaust port and said gas inlet port is exhausted, When supplying the said gas into the said vacuum chamber from the said gas inlet port installed so that the space to the upper direction of the surface of the said sample may be exhausted. A plasma processing method in which the gas is supplied into the vacuum chamber from the gas introduction port provided near the exhaust port rather than the sample electrode. The said shortest flow path which connects the said exhaust port and said gas inlet port is exhausted, When supplying the said gas into the said vacuum chamber from the said gas inlet port installed so that the space to the upper direction of the surface of the said sample may be exhausted. A plasma processing method in which the gas is supplied into the vacuum chamber from the gas introduction port provided below the sample electrode. The said shortest flow path which connects the said exhaust port and said gas inlet port is exhausted, When supplying the said gas into the said vacuum chamber from the said gas inlet port installed so that the space to the upper direction of the surface of the said sample may be exhausted. And the gas is supplied from the gas inlet toward the exhaust port. The said shortest flow path which connects the said exhaust port and said gas inlet port is exhausted, When supplying the said gas into the said vacuum chamber from the said gas inlet port installed so that the space to the upper direction of the surface of the said sample may be exhausted. And the gas is supplied from the gas inlet to the exhaust device for performing the exhaust. The said shortest flow path which connects the said exhaust port and said gas inlet port is exhausted, When supplying the said gas into the said vacuum chamber from the said gas inlet port installed so that the space to the upper direction of the surface of the said sample may be exhausted. And a plasma processing method for supplying the gas into the vacuum chamber from the gas introduction port provided at a portion not in contact with the plasma even when generating a plasma. The said shortest flow path which connects the said exhaust port and said gas inlet port is exhausted, When supplying the said gas into the said vacuum chamber from the said gas inlet port installed so that the space to the upper direction of the surface of the said sample may be exhausted. The plasma processing method of supplying the gas from the gas inlet to the vacuum chamber while shielding from the plasma by a shielding plate disposed near the gas inlet even when generating a plasma. In the plasma processing method for introducing impurities into a sample or a film on the surface of the sample, Mounting the sample on the sample electrode in the vacuum chamber, Exhaust the inside of the vacuum chamber from the exhaust port of the vacuum chamber, After setting the exhaust flow rate from the vacuum chamber through the exhaust port to zero, the vacuum chamber is formed from the gas inlet port provided so that the shortest flow path connecting the exhaust port and the gas inlet port of the vacuum chamber avoids the space above the surface of the sample. The gas is supplied into the chamber, and the flow of the gas supplied from the gas inlet of the vacuum chamber into the vacuum chamber is directed to the exhaust port while avoiding an upward space of the surface of the sample; The supply flow rate of the gas from the gas inlet is made 0, A plasma processing method comprising generating plasma in the vacuum chamber by supplying high frequency power to a plasma source to introduce impurities into the sample or the film on the surface of the sample. 10. The gas inlet of claim 9, wherein after the exhaust flow rate from the vacuum chamber through the exhaust port is zero, the shortest flow path connecting the exhaust port and the gas inlet port is installed to avoid the space above the surface of the sample. And the gas is supplied into the vacuum chamber from the gas inlet provided at a portion closer to the exhaust port than the sample electrode when the gas is supplied into the vacuum chamber. 10. The gas inlet of claim 9, wherein after the exhaust flow rate from the vacuum chamber through the exhaust port is zero, the shortest flow path connecting the exhaust port and the gas inlet port is installed to avoid the space above the surface of the sample. And the gas is supplied into the vacuum chamber from the gas introduction port provided at a portion below the sample electrode when the gas is supplied into the vacuum chamber. 10. The gas inlet of claim 9, wherein after the exhaust flow rate from the vacuum chamber through the exhaust port is zero, the shortest flow path connecting the exhaust port and the gas inlet port is installed to avoid the space above the surface of the sample. And the gas is supplied from the gas inlet toward the exhaust port when the gas is supplied into the vacuum chamber. 10. The gas inlet of claim 9, wherein after the exhaust flow rate from the vacuum chamber through the exhaust port is zero, the shortest flow path connecting the exhaust port and the gas inlet port is installed to avoid the space above the surface of the sample. And when supplying the gas into the vacuum chamber, the gas is supplied from the gas inlet toward the exhaust device that performs the exhaust. The plasma according to claim 9, wherein when the gas is supplied into the vacuum chamber from the gas introduction port provided so that the shortest flow path connecting the exhaust port and the gas introduction port avoids an upward space of the surface of the sample. And the gas is supplied into the vacuum chamber from the gas inlet provided at a portion which is not in contact with the plasma when generating the gas. 10. The gas inlet of claim 9, wherein after the exhaust flow rate from the vacuum chamber through the exhaust port is zero, the shortest flow path connecting the exhaust port and the gas inlet port is installed to avoid the space above the surface of the sample. And the gas is supplied into the vacuum chamber from the gas inlet provided at a portion shielded by the shielding plate from the plasma when the plasma is generated when the gas is supplied into the vacuum chamber. In the plasma processing method for introducing impurities into a sample or a film on the surface of the sample, Mounting the sample on the sample electrode in the vacuum chamber, Supplying gas into the vacuum chamber from the gas inlet of the vacuum chamber while exhausting the inside of the vacuum chamber from the exhaust port of the vacuum chamber, When the volume of the vacuum chamber is V (L: liter), the pressure in the vacuum chamber is p (Torr), and the flow rate of the gas supplied is Q (Torr · L / s), V · p / Q> 1 (s A plasma processing method in which impurities are introduced into a film of the sample or the sample surface by generating a plasma in the vacuum chamber by supplying a high frequency power to a plasma source while satisfying the relation of 17. The plasma processing method according to claim 16, wherein the plasma processing method satisfies a relationship in which V · p / Q &gt; 5 (s) is generated. A vacuum container having a vacuum chamber, and having an exhaust port for exhausting the inside of the vacuum chamber, and a shortest flow path connected to the exhaust port to avoid an upward space on the surface of the sample, and a gas inlet for supplying gas into the vacuum chamber; A sample electrode for mounting the sample in the vacuum chamber, An exhaust device connected to an exhaust port of the vacuum container to exhaust the inside of the vacuum chamber; A gas supply device connected to the gas inlet for supplying gas into the vacuum chamber; Plasma source, A high frequency power supply for supplying high frequency power to the plasma source; Plasma is supplied into the vacuum chamber by supplying the high frequency power to the plasma source while setting the exhaust flow rate from the vacuum chamber through the exhaust port to 0 and supplying the gas from the gas inlet to 0. And a control device for generating and controlling the introduction of impurities into the sample or the film on the surface of the sample. 19. The plasma processing apparatus according to claim 18, wherein the gas introduction port is provided at a portion closer to the exhaust port than the sample electrode. 19. The plasma processing apparatus of claim 18, wherein the gas inlet is provided at a portion below the sample electrode. 19. The plasma processing apparatus of claim 18, wherein the gas inlet is provided to blow the gas toward the exhaust port. 19. The plasma processing apparatus of claim 18, wherein the gas inlet is provided to blow the gas toward the exhaust device. 19. The plasma processing apparatus according to claim 18, wherein the gas inlet is provided at a portion that does not contact the plasma when generating the plasma. 19. The plasma processing apparatus of claim 18, further comprising a shielding plate on which the gas inlet is shielded from the plasma when the plasma is generated. 19. The plasma processing apparatus of claim 18, wherein the sample electrode is disposed in the vacuum container so that the distance between the edge of the sample electrode and the inner wall surface of the vacuum container is uneven.

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